Oligomer composition and products made therefrom

ABSTRACT

An oligomer vulcanizing agent and products made therefrom are described herein. The oligomer composition has the following formula:   WHEREIN R1, R2, R3, R4 and R5 can each be selected from the lower alkyl group having 1 to 10 carbon atoms and x can range between 1 and 7, and n can range between 0.5 and 15.

ilniied States Patent Shim OLIGOMER COMPOSITION AND PRODUCTS MADE THEREFROM Kyung S. Shim. Dobbs Ferry. N.Y.

Staufler Chemical Company. Westport. Conn.

Filed: Sept. 25, 1972 Appl. No.: 291,855

Related U.S. Application Data Inventor:

Assignee:

Division of Ser. No. 120,731, March 3, I971, Pat.

No. 3,72548l, which is a continuation of Ser. No. 800,71 1. Feb I9, 1969, abandoned.

U.S. Cl. 260/79.5 C, 260/4 R, 260/4 AR, 260/5, 260/795 P, 260/795 A. 260/795 8, 260/97, 260/583 EE, 260/775, 260/795, 260/778 Int. Cl. C08f 27/06 Field of Search 260/795 B, 79.5 C, 79.5 P, 260/795 A, 5, 4 R, 4 AR. 97. 775, 798

References Cited UNITED STATES PATENTS 12/1949 Beaver 2. 260/795 C Irimury li.\wnim'rHarry Wong, Jr.

{57] ABSTRACT An oligomer vuleanizing agent and products made therefrom are described herein. The oligomer composition has the following formula:

wherein R,, R R R and R can each be selected from the lower alkyl group having 1 to l0 carbon atoms and can range between 1 and 7, and n can range between 0.5 and 15.

6 Claims, N0 Drawings I OLIGOMER COMPOSITION AND PRODUCTS MADE TI-IEREFROM This is a division of application Ser. No. 120,731, filed Mar. 3, 1971, now U.S. Pat. No. 3,725,481, which was issued on Apr. 3, 1973, and which in turn is a continuation ofU.S. Ser. No. 800,71 I, filed Feb. 19, 1969, and now abandoned.

BACKGROUND OF THE INVENTION In the art of vulcanizing rubber compositions, it is the practice to admix the particular rubber material with additive compounds such as process oils, organic acids and zinc oxide. These rubber materials can be selected from any number of compositions useful in a vulcanizing process, such as, natural rubber or synthetic rubbers. The synthetic rubbers can be described as the alpha-olefin hydrocarbons such as ethylene/propylene copolymers, ethylene/butylene copolymers, ethylenel propylene/diene terpolymers, ethylene/l-butene/diene terpolymers, styrene/butadiene copolymers, and neoprene. After these materials are thoroughly intermixed together, a vulcanizing agent is added thereto. The combination of ingredients are then heated in a conventional apparatus and vulcanized into useful products.

The most commonly used vulcanizing agent within these formulations is free sulfur. However, when using sulfur to vulcanize the rubber materials, a noxious odor is given off when the rubber material is finally cured, which is objectionable. Moreover, the end product is too scorchy during the curing thereof. Also, blooming problems are encountered. In order to overcome these problems, amino compositions containing a substantial amount of sulfur were formulated and used in lieu of the free sulfur. However, these materials have not been notably successful because the rubber formulation will have either too high or too low a viscosity or too scorchy or will have a high reversion rate along with a long curing rate or have poor blooming properties.

BRIEF DESCRIPTION OF THE INVENTION It has been discovered that an oligomer vulcanizing agent composition can be used successfully to vulca nize rubber compositions into useful products. The oligomer composition has the following formula:

DETAILED DESCRIPTION OF THE INVENTION In the practice ofthe present invention, the oligomer vulcanizing agent of the present invention is manufactured by first intermixing a primary alkyl amine and a secondary alkyl amine in a water, alkali hydroxide and organic solvent. This combination of materials is thoroughly mixed together. and maintained under agitation conditions while being cooled in an ice bath. While this combination of materials is thoroughly stirred, a sulfur chloride material is slowly added over a period of from about 0.25 to about 2 hours while maintaining the reaction temperature at between about 0 and 50C. After additional stirring, the mixture is then cooled to room temperature. When the reaction temperature is cooled to room temperature, an organic layer will form which is separated, washed and dried over anhydrous drying material to remove all the water. The product is a yellow oily material.

The primary alkyl amine useful in the present invention can be the lower alkyl amines having from 1 to 10 carbons atoms. Exemplary of the primary alkyl amines useful with the present invention are methylamine, ethylamine, propylamine, isopropy'lamine, butylamine, isobutylamine, tertiary butylamine, pentylamine, hexylamine and mixtures thereof. The secondary alkyl amines useful with the present invention are those with alkyl groups contain from 1 to 10 carbon atoms. Exemplary secondary amines are dimethylamine, diethylamine, dipropylamine, di-isopropylamine, dibutylamine, (ii-isobutylamine, di-tertiary butylamine, dipentylamine, dihexylamine and mixtures thereof. The alkali hydroxide is preferably selected from the sodium and potassim alkali metal hydroxides, although alkali carbonates such as sodium carbonate can be used. The organic solvent can be selected from the group consisting of hexane, pentane, ether, chloroform, carbon tetrachloride and the like. The sulfur chloride can be sulfur monochloride, sulfur dichloride, dichlorotrisulfane, dichlorotetrasulfane as represented by the formula S Cl where x can range between 1 and. 7.

The product formed is an oligomer having the following formula:

wherein R R R R and R can each be a lower alkyl having from 1 to 10 carbon atoms and wherein the average numerical value for x will range between 1 and 7, preferably around 2 to 5 and n can range between 0.5 and 15. The average numerical values for x and n will, of course, depend on the amount of ingredients that are used in the initial reaction. Thus, up to about 15 moles of the primary amine can be reacted with at least 2 moles of the secondary amines and up to 16 moles of sulfur chloride material can be employed. Thus, the formulator can select the average number of x and n for the end result desired.

The oligomer composition in the present invention can then be used in vulcanizing rubber compositions. Thus, the oligomer composition can be intermixed with natural rubbers or the synthetic rubbers in an amount ranging between 0.5 to about 10 parts per parts of the rubber composition. Typical synthetic rubbers includes styrene-butadiene, polybutadiene, polyisoprene, acrylonitrile-butadiene, ethylene-propylene-diolefin, isobutylene-isoprene, polychloroprene and the like. After the oligomer vulcanizing agent has been added thereto, the rubber composition is fully cured in a conventional manner.

The following examples illustrate the merits of the present invention:

EXAMPLE 1 In a two liter flask, equipped with a stirrer, thermometer and dropping funnel, was placed 800 milliliters of water, 200 milliliters of hexane, 1 mole of dimethylamine, 1 mole of tertiary butylamine, and 4 moles of sodium hydroxide. The material was cooled in an ice bath. To the stirring solution was added 2 moles of sulfur monochloride dropwise over a period of 1 hour while maintaining the reaction temperature at between and 30C. After the reaction mixture had cooled to room temperature, it was stirred for an additional hour. An organic layer was separated, washed with water, and dried over anhydrous magnesium sulfate. The solvent was removed on a rotary evaporator to give a yellow oily material. In order to remove all other volatile materials which may be present within the mixture, the yellow oily material was subjected to reduced pressure at 0.02 millimeters at room temperature to give 65.5 grams of the yellow oil. Analysis of this material indicated the presence of 57.3% sulfur.

EXAMPLE 2 This example describes the use of the oligomer composition of Example 1 as a curing agent for commercial rubber compositions. Thus, a master batch was prepared by mixing 40 parts of carbon black, 4 parts zinc oxide, 2 parts stearic acid, 1 part antioxidant, and 1 part benzothiazole disulfide with each 100 parts of natural rubber. Portions of this material were then used to prepare two different stocks. Thus, 2.5 parts of free sulfur was added to the first stock and 1.8 parts of the curing agent of Example 1 was added to the second stock. Each of the stocks were then cured in the conventional manner with the following results:

This example describes the use of the curing agent of Example 1 for commercial styrene/butadiene rubber compositions. Thus, 40 parts carbon black, 16 parts napthenic process oil, 4 parts zinc oxide, 2 parts stearic acid, 1 part antioxidant, 1.5 parts mercaptobenzothiazole were blended with 100 parts styrene butadiene rubber. Portions of this material were then used to prepare stocks. Thus, 2 parts of free sulfur was added to the first portion and 2.75 parts of the curing agent of Example 1 was added to the second portion. These stocks were then cured in a conventional manner and the following data resulted:

TABLE 11 Oscillating Disc Rheograph; 320F. 900 cpm Minimum Viscosity, in-lbs Maximum Viscosity. in-lhs 69 Minutes to 1 in-lb increase 4.3 Minutes to 90% max. viscosity l4 Cure Rate, in-lbs/minutc 4.4

EXAMPLE 4 In a two liter flask, equipped with a stirrer, thermometer and dropping funnel, was placed 300 milliliters of water, 150 milliliters of hexane, 0.5 mole of dibutylamine, 0.5 mole of tertiary butylamine, and 2.2 moles of sodium hydroxide. The material was cooled in an ice bath. To the stirring solution was added 1 mole of sulfur monochloride dropwise over a period of 1 hour while maintaining the reaction temperature at between 15 and C. After the reaction mixture had cooled to room temperature, it was stirred for an additional hour. An organic layer was separated, washed with water, and dried over anhydrous magnesium sulfate. The solvent was removed on a rotary evaporator to give a yellow oily material. In order to remove all other volatile materials which may be present within the mixture, the yellow oily material was subjected to reduced pressure at 0.01 millimeters at room temperature to give 149 grams of the yellow oil. Analysis of this material indicated the presence of 32.43% sulfur.

EXAMPLE 5 In a two liter flask, equipped with a stirrer, thermometer and dropping funnel, was placed 300 milliliters of water, 150 milliliters of hexane, 0.5 mole of dibutylamine, 1 mole of n-propylamine, and 2.2 moles of sodium hydroxide. The material was cooled in an ice bath. To the stirring solution was added 1 mole of sulfuur monochloride dropwise over a period of 1 hour while maintaining the reaction temperature at between 15 and 30C. After the reaction mixture had cooled to room temperature, it was stirred for an additional hour. An organic layer was separated, washed with water, and dried over anhydrous magnesium sulfate. The solvent was removed on a rotary evaporator to give a yellow oily material. In order to remove all other volatile materials which may be present within the mixture, the yellow oily material was subjected to reduced pressure at 0.02 millimeters at room temperature to give 131.0 grams of the yellow oil.

What is claimed is:

1. A vulcanized product obtained by heating a rubber composition selected from the group consisting of alpha-olefin hydrocarbon synthetic rubbers and natural 6 rubber and mixtures thereof in the presence of an effective amount for vulcanization of a curing agent consisting of an oligomer composition having the following formula:

wherein R R R and R each are a lower alkyl group having from I to carbon atoms, R is a tertiary butyl group, x ranges between I and 7, and n ranges between 0.5 and 15.

2. A vulcanized product in accordance with claim 1 wherein said curing agent is present in an amount ranging between 0.5 to about 10 parts per 100 parts of the rubber composition.

3. A vulcanized product in accordance with claim 1 wherein x has a value of 2.

4. A vulcanized product in accordance with claim 1 wherein R R R and R are methyl and R is tertiary 6 butyl.

5. A vulcanized product in accordance with claim 1 wherein R is tertiary butyl.

6. A vulcanized product as claimed in claim 1 wherein the synthetic rubbers are selected from the group consisting of ethylene-propylene, ethylenebutylene, ethylene-propylene-diene, styrenebutadiene, neoprene, polybutadiene, synthetic polyisoprene acrylonitrile-butadiene, isobutylene-isoprene.

and polychloroprene copolymers.

* l =l .l

age UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patem; No. ,9 5 Dated January 2 1 1975 InventorQs) y g Sup Shim It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Col. 2, iine 20, insert which aft er "groups"; Col. 2, line 26, change "potessim" te potassifim Col. 5, Table I, right hand colunin undef the heading "2nd Stock", change "5.3" and "0.05" to 8.5 and 0.06 respectively;

' (301. h, Table II, right hand column under the heading "2nd Stock", change "507" to 5.7

. Col. 4, line +5, change ":Euur" to fur Signed and sealed this 29th day of April 1975.,

(SEAL) Attest:

C. MARSHALL DANN RUTH C. MASON Commissioner of Patents Attesting Officer and Trademarks 

2. A vulcanized product in accordance with claim 1 wherein said curing agent is present in an amount ranging between 0.5 to about 10 parts per 100 parts of the rubber composition.
 3. A vulcanized product in accordance with claim 1 wherein x has a value of
 2. 4. A vulcanized product in accordance with claim 1 wherein R1, R2, R3 and R4 are methyl and R5 is tertiary butyl.
 5. A vulcanized product in accordance with claim 1 wherein R5 is tertiary butyl.
 6. A vulcanized product as claimed in claim 1 wherein the synthetic rubbers are selected from the group consisting of ethylene-propylene, ethylene-butylene, ethylene-propylene-diene, styrene-butadiene, neoprene, polybutadiene, synthetic polyisoprene, acrylonitrile-butadiene, isobutylene-isoprene, and polychloroprene copolymers. 